BGA Package Mount Manual · Epson has prepared this document carefully and accurately as much as...

Rev.1.0

BGA

Package Mount Manual

This manual describes notes on using Epson BGA products. It is the responsibility of the customer to optimize the process

to obtain the desired results.

ii Seiko Epson Corporation BGA Package Mount Manual

（Rev.1.0）

NOTICE

The content of this document is subject to change without notice.

1. This document may not be copied, reproduced, or used for any other purpose, in whole or in part, without the consent of Seiko Epson

Corporation (“Epson”).

2. Before purchasing or using Epson products, check with our sales representative for the latest information. Always consult Epson web site or

other sources for the latest information.

3. Information provided in this document is for reference only. Epson makes no guarantees against any infringements of or damages to a third

party intellectual property rights or any other rights resulting from the information. Epson does not give any licenses to use the intellectual

property rights or any other rights of a third party or Epson under this document.

4. When using Epson products, evaluate mounting and soldering thoroughly, and use the Epson products within the guarantee range specified by

Epson. Epson shall have no liability for malfunctions, accidents resulting in injury or death, fire accident or social damages arising out of the

use of Epson products beyond such specified by Epson.

5. Epson has prepared this document carefully and accurately as much as possible, but Epson does not guarantee that the information presented

herein is error-free. Epson assumes no responsibility for any damages caused by the customers resulting from information errors in this

document.

6. Epson products listed in this document and their associated technologies may not be used in equipment or systems that are prohibited to

manufacture, use or sell under the laws, regulations, or rules in Japan or any other countries. Furthermore, Epson products and their associated

technologies may not be used for the development, etc., of weapons of mass destruction, for military uses, or other military applications. If

exporting Epson products or their associated technologies, be sure to comply with the Foreign Exchange and Foreign Trade Control Act in

Japan and other export-related laws and ordinances in Japan and any other countries. And follow the required procedures as provided by the

relevant laws and ordinances.

7. Epson assumes no responsibility if our products are used in violation of conditions listed in this document and such use results in damage.

8. For details of environmental compatibility etc. of Epson products, check Epson's web site.

9. Epson assumes no responsibility if our products' failure or characteristic fluctuation occurs due to external factors (electrostatic breakdown

ESD, overvoltage / overcurrent EOS, thermal stress, mechanical stress, environmental atmosphere) in the product handling, mounting, and

customer's process.

Also, follow the conditions of individual specifications such as storage time before opening, storage time after opening, etc. for products that

require moisture-proof packaging.

©SEIKO EPSON CORPORATION 2018, All rights reserved.

BGA Package Mount Manual Seiko Epson Corporation iii （Rev.1.0）

Table of Contents

1．Outline ......................................................................................................................... 5

1.1 BGA Package Structure ............................................................................................................. 5

1.2 BGA Photo ................................................................................................................................... 5

1.3 BGA Line-up ................................................................................................................................ 6

2. Soldering .................................................................................................................... 7

2.1 Soldering for BGA Package ........................................................................................................ 7

2.2 Reflow Soldering Process Flow ................................................................................................. 8

3. PCB Design Guide ..................................................................................................... 9

3.1 Precautions for PCB Design ...................................................................................................... 9

3.2 Land Pattern and Solder Resist Design, NSMD and SMD ...................................................... 9

3.3 PCB Land Size for BGA ............................................................................................................ 10

3.4 PCB Land Surface Treatment ................................................................................................... 10

3.5 PCB Warp ................................................................................................................................... 10

4. Solder Printing .......................................................................................................... 11

4.1 Solder Paste ............................................................................................................................... 11

4.2 Stencil Design ............................................................................................................................ 12

4.3 Solder paste supply .................................................................................................................. 13

4.4 Squeegee .................................................................................................................................... 13

4.4.1 Polyurethane Rubber Squeegee .......................................................................................... 13

4.4.2 Metal Squeegee .................................................................................................................... 13

4.4.3 Plastic Squeegee .................................................................................................................. 13

4.5 Solder Printing ........................................................................................................................... 14

5．Mounting ................................................................................................................... 15

5.1 Precautions for Mounting BGA ................................................................................................ 15

5.1.1 Taking out from Carrier Tape or Tray .................................................................................... 15

5.1.2 Mounting on PCB .................................................................................................................. 15

6. Reflow Soldering ..................................................................................................... 16

6.1 Reflow Soldering Oven ............................................................................................................. 16

6.1.1 Preheating Zone .................................................................................................................... 16

6.1.2 Reflow Zone .......................................................................................................................... 16

6.1.3 Cooling Zone ......................................................................................................................... 16

6.2 Reflow Profile ............................................................................................................................. 17

6.3 Guidelines for Epson BGA Soldering ...................................................................................... 17

6.3.1 Recommended Reflow Soldering conditions : MSL2a ......................................................... 18

6.3.2 Recommended Reflow Soldering conditions : MSL3 ........................................................... 19

7. Cleaning ................................................................................................................... 20

7.1 Cleaning after BGA Soldering .................................................................................................. 20

7.2 General PCB Cleaning .............................................................................................................. 20

7.2.1 PCB Cleaning ........................................................................................................................ 20

iv Seiko Epson Corporation BGA Package Mount Manual

（Rev.1.0）

7.2.2 Cleaning Method ................................................................................................................... 20

7.2.3 Water Cleaning ...................................................................................................................... 20

7.2.4 No Cleaning........................................................................................................................... 20

7.3 Others ......................................................................................................................................... 20

8. Rework ...................................................................................................................... 21

9．General Precautions for Use of Semiconductor Devices ...................................... 22

9.1 Introduction ................................................................................................................................ 22

9.2 Storage ....................................................................................................................................... 22

9.3 Design and Handling ................................................................................................................. 22

Revision History ............................................................................................................. 24

1． Outline

BGA Package Mount Manual Seiko Epson Corporation 5

（Rev.1.0）

1． Outline

Ball grid array package (BGA) is a surface-mount type package. And BGA is an area array, in which the

external terminals, namely solder balls, are arranged in a matrix on the bottom surface of the package.

Unlike the conventional QFP (Quad Flat Package), BGA does not need to arrange the mounting printed circuit

board (PCB) lands around the package, since the external terminals of BGA are on the bottom surface of the

BGA. So in PCB design, it is an advantage for more terminals layout and high density mounting application.

Epson uses “Saw Dicing” method for the singulation process of BGA. And Epson has various package line-ups

with different package size, external pin pitch and pin counts according to the application.

1.1 BGA Package Structure

Epson BGA structure is as follows:

> IC chip is attached to the interposer, printed circuit board (PCB).

> PCB terminal and IC pad are connected by wire-bonding.

> Molded by epoxy resin.

> Solder balls are mounted on the bottom surface of the package as external terminals.

PCB is used as the interposer, so external terminals’ flexible layout is easier to design.

Epson can supply stacked-type custom BGA also.

Fig. 1.1 BGA package Sectional View

1.2 BGA Photo

Fig. 1.2 Package Top Surface Fig. 1.3 Package Bottom Surface (Solder Ball Side)

Epoxy Resin

Solder Ball

IC Chip

Wire Bond

PCB (Interposer)

Adhesive

1． Outline

6 Seiko Epson Corporation BGA Package Mount Manual

（Rev.1.0）

1.3 BGA Line-up

Table 1.1 BGA Line-up Unit : mm

BGA package type Body size

D , E (Nom.) Package height

A (Max.) Ball pitch

e (Nom.)

PBGA Plastic Ball Grid Array 17sq 1.3 , 1.7 1.0

PFBGA Plastic Fine-pitch Ball Grid

Array

5sq ,6sq 7sq , 8sq

10sq , 12sq 14sp, 16sq

1.2 0.5 , 0.65 , 0.8

VFBGA Very-thin Fine-pitch Ball

Grid Array

4sq , 5sq 6sq , 7sq

8sq , 10sq 1.0 0.5 , 0.8

*) Customized tool may be required depending on the above combinations.

Please refer to our website and brochure.

Table 1.2 Design Rule for External Terminals *1) Unit : mm

Ball pitch *2) e (Nom.)

Solder ball diameter before

solder ball attach

BGA package PCB land opening

diameter φc

BGA package solder ball height

*3) A1

BGA package solder ball

diameter *4) φb

0.50 0.30 0.28 0.23 0.31

0.65 0.30 0.30 0.22 0.32

0.80 0.40 0.40 0.30 0.43

1.00 0.50 0.50 0.40 0.50

*1) This is the design rule for the standard specification.

*2) The distance between adjacent ball terminals.

*3) Height of solder ball tip from solder resist surface.

*4) Solder ball diameter after completing BGA package may differ depending on the thickness of the

solder resist and the opening diameter of the land.

Fig. 1.4 BGA Dimension

IC Chip

Solder Ball (Sn-Ag-Cu)

エポキシ樹脂 A A1

E

D

Index

Cu Wiring

PCB

φb

φc

<Sectional View>

2. Soldering


（Rev.1.0）

2. Soldering

2.1 Soldering for BGA Package

As the soldering method for BGA package that is one of the surface mount devices (SMD), reflow process is

recommended generally. Reflow process is as follows. Firstly solder paste is printed on PCB, then surface mount

devices are mounted on the PCB, and then the PCB with SMD is soldered by the heat of a reflow oven. This

technology is called “Surface mount technology (SMT)”, and SMT is generally used for SMD. Reflow heating

methods include infrared (IR) method, hot air method (convection method), infrared (IR) hot air combined

method, hot plate method, and so on.

In the reflow soldering process, SMD soldering accuracy does not depend on SMD mounting accuracy.

Soldering accuracy depends on solder self-alignment by the solder surface tension. *1) Therefore, when

designing PCB, it is necessary to design the land and PCB considering the characteristics of this self-alignment

function.

For BGA package soldering, hot air method or IR hot air combined method is recommended. If only IR is

used, solder balls on the bottom surface of the BGA are hard to obtain enough heat for soldering, because IR

might be blocked by molded package body, especially for large size BGA packages.

*1) Solder self-alignment: A certain level of SMD mounting shift will be corrected by the solder surface

tension force during reflow soldering. Solder self-alignment depends on the solder surface tension force and

package weight, so it’s effective in light packages. But solder self-alignment effect might not occurred, when

there is a huge offset between PCB land and BGA solder ball.

2. Soldering


（Rev.1.0）

2.2 Reflow Soldering Process flow

Table below shows the typical and most regular used reflow soldering process flow for BGA package

soldering.

Table 2.2 Reflow Soldering Process Flow

Process Material Machine, Jig, etc.

1 Printing [Chapter 4] PCB [Chapter 3] Solder paste

[Section 4.1, 4.3]

Printing machine Stencil [Section 4.2] Squeegee [Section 4.4]

(2) (Printing inspection) ――― Inspection unit SPI

3 Mounting [Chapter 5]

SMD BGA, Chip components, Connector, etc.

SMD mounter

4

Reflow soldering [Chapter 6] Preheating [Section 6.1.1] Reflow [Section 6.1.2] Cooling [Section 6.1.3]

PCB after SMD mounted. Reflow oven Reflow profile [Section 6.2] N2 gas

5 Cleaning [Chapter 7] PCB after soldering. Cleaning machine Cleaner

(6) (Function test) ――― In-circuit tester

(7) (Visual inspection) ――― Inspection unit AVI

* For details of each process, please refer to the explanation page.

(2), (6) and (7) are the inspection process, so explanation is omitted.

3. PCB Design Guide


（Rev.1.0）

3. PCB Design Guide

3.1 Precautions for PCB Design

There are two types of PCB mounting pad, Non-Solder Mask Defined (NSMD) and Solder Mask Defined

(SMD). In general, it is said that the solder joint strength of NSMD is higher than that of SMD, because in NSMD, solder

joint exists not only land pattern surface but also land pattern side wall. But sometimes solder printability for

SMD is better than that for NSMD because of printing parameter and/or stencil design. So please select NSMD

or SMD according to application.

3.2 Land Pattern and Solder Resist Design, NSMD and SMD

In NSMD, land size is defined by the land pattern size. And in SMD, land size is defined by the solder resist

opening size.

After soldering

Fig. 3.1 NSMD Sectional View Fig. 3.2 SMD Sectional View

Table 3.1 (Reference) Joint Strength Comparison of NSMD and SMD

Joint strength between land and PCB *1) NSMD ＜＝ SMD

Joint strength between land and solder *2) NSMD ＞＝ SMD

*1) As land pattern is covered by solder resist, joint strength between land and PCB of SMD is higher

than that of NSMD.

*2) As solder covers not only land pattern top surface but also land pattern side wall, joint strength

between land and solder of NSMD is higher than that of SMD.

PCB PCB

PCB PCB

BGA BGA

Land Solder resist

Solder junction

3. PCB Design Guide


（Rev.1.0）

3.3 PCB Land Size for BGA

Typically, it is best to design the land size of the mounting board equal to the mounting component for better

stress distribution. However, optimum size may depend on the customer's mounting conditions and PCB. To

decide the PCB land size, please design within the range of BGA interposer opening size +/- 50um.

Please decide the PCB land structure and the PCB land dimension based on the evaluation results of joint

strength, reliability, mounting property, solder paste printability and so on.

Table 3.2 (Reference) Examples of PCB Land Diameter Unit : mm

Ball pitch BGA PCB

Land diameter (Nom) Land diameter (Nom.)

0.50 0.28 0.28 ±0.05

0.65 0.30 0.30 ±0.05

0.80 0.40 0.40 ±0.05

1.00 0.50 0.50 ±0.05

3.4 PCB Land Surface Treatment

Leaving PCB in the atmosphere might oxidize the land surface of PCB, and this oxidation may affect the

solder wettability during soldering. It is better to use protective film coating or plating to prevent this oxidation.

In general, Organic Solderability Preservatives (OSP) and Ni/Au plating are used for PCB land surface oxidation

prevention treatment. So adoption of these treatments is strongly recommended.

3.5 PCB Warp

Solder connection between the component and the PCB may not be obtained or the solder joint reliability may

be adversely affected, if the warp of the PCB is large during and after reflow. In the PCB designing, please select

the material with high warpage resistance, and equalize the ratio occupied by conductor on the each layer of the

PCB. Additionally, in PCB components layout design, please do not place SMD including BGA near the place with

high stress concentration during soldering and actual use. Stress concentration places are, for example in the

vicinity of switches and connectors, on the backside of switches and connectors, and movable part such as hinge.

4. Solder Printing


（Rev.1.0）

4. Solder Printing

4.1 Solder Paste

Solder paste consists of solder particles, flux, surfactant, thixotropic agent and so on. Since there are many

kinds of solder paste, for each solder paste it is necessary to determine the reflow temperature profile

individually.

The composition and size of the solder particles in the solder paste are determined depending on the

application, mount land pitch and so on. Solder paste with narrow particle distribution has better soldering

stability.

Full attention is required for selecting the particle size of solder paste. Smaller solder particle tend to have

surface more oxidation during storage, printing and reflow. This may lead to “head-in-pillow” failure and worsen

the solder wettability.

As Epson standard, Sn-3.5Ag-0.75Cu solder ball is used for external terminals of BGA. But sometimes other

composition solder ball is used depending on the customer’s requirement, so please check each product

specification and confirm the solder paste compatibility. In addition, please refer to the above and select the solder paste based on the result from sufficient evaluation

of solder wettability, the state of generation of intermetallic compounds and so on.

Table 4.1 (Reference) Solder Paste Structure

Component Function

Solder particle

As the solder particles melt and the solder wetting progresses, the solder particles in solder paste and the solder balls of BGA melt together uniformly. As a result, electrical connection and mechanical joint strength are obtained after cooling.

Flux Flux reduces the oxide film on each terminal surface, and prevents re-oxidation of the solder surface during reflow heating, and accelerates molten solder fluidity.

Surfactant Surfactant is used in a small amount to mix flux, solder and other components uniformly.

Thixotropic agent Thixotropic agent is added to the solder paste to keep the shape of the solder paste after printing, and holding the mounted components.

Table 4.2 (Reference) Solder Melting Point

*1) Peak temperature: Temperature at the maximum heat absorption point of DSC curve.

Solder paste composition

Melting temperature (°C)

Solidus Peak

temperature *1)

Liquidus-line

Sn - 3.5Ag - 0.75Cu 218 219 219

Sn - 3.0Ag - 0.5Cu 217 219 220

Sn - 1.0Ag - 0.5Cu 217 219 227

4. Solder Printing


（Rev.1.0）

4.2 Stencil Design

Since the design of the stencil greatly affects the SMT process quality (solderability, standoff, solder bridge

and so on), proper stencil design is necessary. The volume and stability of solder paste to be transferred to PCB is

determined by the design of stencil specifications, stencil thickness, opening size for solder filling, planar shape

and cross sectional shape. In typical solder printing process, to obtain a stable solder paste transfer volume, stencil property such as small

physical variation material and excellence stencil releasing after solder printing should be selected. Also, when

mounting of multiple SMDs, special attention is required on designing of printing mask due to optimum solder

paste volume and thickness that might be different between each component. Excessive or insufficient and unstable of solder paste might occur, if selection of stencil property and design

are incorrect. This causes defective solder joint. Stencil selection and design with sufficient evaluation of

mounting and soldering is necessary.

Fig. 4.1 Sectional View of Stencil and PCB

Table 4.3 (Reference) Stencil Design Unit : mm

Ball pitch PCB land diameter A (NSMD) , C (SMD)

Stencil opening diameter B , D

Stencil thickness E

0.50 0.28 0.28 ±0.05 0.15 (Reference)

0.65 0.30 0.30 ±0.05 0.15 (Reference)

0.80 0.40 0.40 ±0.05 0.15 (Reference)

1.00 0.50 0.50 ±0.05 0.15 (Reference)

Table 4.4 (Reference) Failure Mode Caused by Solder Paste Printing Solder paste printing

condition Main failure mode

Excessive solder paste > Solder bridge > Solder ball scattering > Component tilt/lifting

Insufficient solder paste > Solder no joint > Solder bad wetting > Head-in-pillow

Stencil

PCB

4. Solder Printing


（Rev.1.0）

4.3 Solder paste supply

Solder paste should be stored under supplier's recommended conditions and use solder paste within supplier's

guaranteed life time. Once container is opened and solder paste is exposed to the environment, please use solder

paste under supplier's warranty conditions and recommended conditions. Please refer to below general precautions for using the solder paste. > Please open the solder paste container after the temperature of solder paste reaches to near room temperature. > Please stir solder paste 10 or 20 times by spatula, or please print a trial printing several times after supplying

adequate solder paste on stencil. > Please don’t return solder paste once used for printing to the original container, please discard it.

4.4 Squeegee

As there are various types of squeegee, please select the optimum according to the PCB, solder paste and

printing machine.

Table 4.5 (Reference) Squeegee Material Comparison

Squeegee material Use for uneven

surface Amount of printed

solder Stencil life Squeegee life

Polyurethane rubber ◎ △ ◎ △

Metal △ ◎ △ ◎

Plastic △ ◎ ○ ○

*) Above is the relative comparison in general. (◎: Excellent, ○: Good, △: Acceptable)

4.4.1 Polyurethane Rubber Squeegee

By using polyurethane rubber as the squeegee material, it is possible to extend the lifetime of the stencil, but

there is a tendency that the volume of printed solder paste becomes lesser than expected. By using this type squeegee on uneven PCB, it is possible to obtain good solder printing.

4.4.2 Metal Squeegee

By using metal material as the squeegee material, it is good for printed solder paste volume, but it tends to

shorten the lifetime of the stencil. By using this type squeegee on even PCB, it is possible to obtain good solder printing.

4.4.3 Plastic Squeegee

By using plastic material as the squeegee material, it is possible to keep the amount of printed solder

equivalent to that of the metal squeegee and to extend the lifetime of the stencil, but the lifetime of the squeegee

itself is inferior to the metal squeegee.

4. Solder Printing


（Rev.1.0）

4.5 Solder Printing

Solder paste is printed on the PCB solder connection land designated for BGA. In general, solder paste is filled

in the stencil hole with a squeegee, and transferred to the required position, with the required thickness through a

stencil separation process.

In order to achieve good quality of solder paste printing, solder paste handling, printing machine maintenance

and setting, such as stencil clearance, printing pressure, and squeegee speed are important. Particularly, solder

paste property varies depending on environment such as temperature, humidity, atmospheric convection and so

on, it is necessary to pay attention to those environmental factors.

After solder printing, please complete the solder reflow process as soon as possible by following solder paste

supplier recommendation.

5．Mounting


（Rev.1.0）

5．Mounting

BGA is to be mounted on the land where the solder paste is printed. For BGA mounting, please use general

component mounting equipment, SMD mounter.

In the reflow soldering method, the final components accuracy after reflow soldering does not reflect the

components mounting accuracy. The shift of alignment in components mounting process, to some extent, is

corrected by the self-alignment during reflow soldering process. So please mount the components within the

range where the position can be corrected by "self-alignment".

Firstly small chip components such as ceramic chip capacitor and so on, should be mounted. Then the large

components such as QFP and so on, should be mounted last. Please decide the mounting order in consideration of

the size of the mounting components and BGA.

5.1 Precautions for Mounting BGA

5.1.1 Taking out from Carrier Tape or Tray

Please be careful not to apply excessive load or impact during component pickup. Also, please do not press the

BGA strongly with parts suction nozzle and so on. BGA package damage and/or solder ball deformation may

occur.

5.1.2 Mounting on PCB

When mounting BGA on the PCB, it is necessary to push the BGA into the printed solder paste on the PCB

land appropriately. But excessive loading and/or pressing may cause the solder bridge failure between BGA

solder balls and the solder ball scattering failure, due to the solder paste collapse. Impact and pressing beyond limit may result in the breakage of BGA package and the deformation of solder

balls. So please decide the mounting parameters after sufficient evaluation.

6. Reflow Soldering


（Rev.1.0）

6. Reflow Soldering

6.1 Reflow Soldering Oven

The outline of the reflow soldering oven that is used for SMD soldering in general, is as follows. The reflow

oven has the following temperature zone arrangement, and it is necessary to set optimum temperature profile and

circumstances for each zone.

Fig. 6.1 Sketch of Reflow Soldering Oven

6.1.1 Preheating Zone

PCB and mounted components are preheated in the preheating zone. Temperature is from about 140 degrees to

about 200 degrees in general. The purpose of preheating is to equalize the temperature of components of various heat capacity mounted on

the PCB, to relieve the sudden thermal shock stress to the components, to activate the flux, and to vaporize the

organic solvent, in order to obtain stable solder joints.

6.1.2 Reflow Zone

Temperature is then raised to the solder melting point, in general from 220 degrees to 260 degrees, for a short

duration. As the solder melting point depends on the solder composition, the reflow temperature for lead-free solder

must be higher than that for conventional lead solder. However, when the reflow heating temperature becomes

higher, oxidation will be accelerated and the wettability tends to become worse. For stable soldering, in order to

prevent accelerated oxidation at high temperature, it is necessary to keep the oxygen concentration low. And also lead-free reflow profile may not be suitable for some components mounted at the same time.

Heatproof guarantee temperature of some components may bring down lead-free reflow profile temperature. So it

is necessary to confirm the heatproof temperature of each component beforehand.

6.1.3 Cooling Zone

Although natural cooling is common, it is recommended to cool down rapidly in order to release the mounted

components from the thermal stress quickly and to obtain a thin and uniform intermetallic compound at the

solder joint.

Preheating zone Reflow zone Cooling zone

Heater Heater Heater

Heater Heater Heater Cooling

Cooling

6. Reflow Soldering


（Rev.1.0）

6.2 Reflow Profile

Below figure shows the reflow temperature profile for typical lead-free solder, Sn-Ag-Cu alloy solder.

Temperature of the soldering position of the mounted components during reflow soldering, is affected by the

following. The structure of mounted components (for example, area array package or peripheral package),

surrounding components layout, components position in the PCB, mounted components density and its heat

capacity will affect the temperature. So please verify the temperature profile at multiple solder joint positions on

the PCB. When setting reflow profile by customer, please refer to the recommended reflow profile from solder paste

supplier, check the temperature profile by using actual reflow soldering oven and actual PCB, and set the

optimum temperature parameter. In general, reflow heating under nitrogen environment is highly recommended because this gives better result

of soldering stability and wettability.

For Epson BGA, please refer to “Guidelines for Epson BGA soldering" in 6.3.

Temperature

300°C－

250°C－

200°C－

150°C－

100°C－

50°C－

0°C | | | | | | | | | | | |

60 120 180 240 300 360 Time (sec)

Fig. 6.2 (Reference) Typical Reflow Temperature Profile *1)

*1) Reprint from “JEITA ET-7407B Fig. 3 Sn-3.0AG-0.5Cu”. About detail, please refer to JEITA standard.

*2) Allowable soldering temperature and soldering time depends on the components and the packages.

Please check the specification of components and packages.

6.3 Guidelines for Epson BGA Soldering

When using Epson BGA, please follow the “Guidelines for Epson BGA soldering” in section 6.3.1 and6.3.2.

Table 6.1 BGA Moisture Sensitivity Levels

Package Type Level Reference for

guideline Floor Life

(≤ 30°C/70% RH)

PFBGA MSL2a 6.3.1 30 days (720 hours)

VFBGA

PBGA MSL3 6.3.2 1 week (168 hours)

Solder melting area: 220 - 250°C

Preheating area: 140 - 220°C

Over 220°C *2): 45 - 90sec

Heating rate < 3 K/sec Cooling rate < 6 K/sec

6. Reflow Soldering


（Rev.1.0）

6.3.1 Recommended Reflow Soldering conditions : MSL2a

This package is surface mount device (SMD). The resistance to soldering heat with SMD depends on storage conditions, soldering methods, and soldering conditions. Please assemble packages according to the following conditions.

Recommended storage conditions

Conditions Time Before opening dry pack: ≦30℃85％RH 1 year

After opening dry pack: ≦30℃70％RH 1 month (720 hours)

Recommended reflow profile

This package should be assembled with IR reflow, full convection, or IR/convection. The allowable number of time with the reflow is max. 2 times. This must be done in the above-mentioned condition (after opening dry pack). Nitrogen reflow is recommended to inhibit the effects of oxidation and improve wettability. * Hand soldering using a soldering iron should be performed under the following

conditions: <Temperature: less than 350 °C, Time: less than 5 sec, Times: twice or less>

Pay sufficient attention not to let a soldering iron contact any parts other than leads.

Recommended bake conditions

When packages exceed the above-mentioned storage conditions after opening the dry pack, please bake them according to the following conditions:

Temperature Time Number of times

125±5℃ 20 - 36 hours Max. 2 times

Storage conditions from the baking to the reflow soldering are the same as the above-mentioned storage conditions.

*if products are shipped in tape & reel, please transfer them to heatproof trays before baking.

(Storage rank： MSL2a)

Pre-heat

140 – 200℃

60 – 120sec

Time above 220℃:

Max. 60sec

Peak temp.： 260℃

Time above 255℃:

Max. 10sec

Time

Te

mp

era

ture

(Pa

ck

ag

e b

od

y s

urf

ace)

6. Reflow Soldering


（Rev.1.0）

6.3.2 Recommended Reflow Soldering conditions : MSL3

This package is surface mount device (SMD). The resistance to soldering heat with SMD depends on storage conditions, soldering methods, and soldering conditions. Please assemble packages according to the following conditions.

Recommended storage conditions

Conditions Time Before opening dry pack: ≦30℃85％RH 1 year

After opening dry pack: ≦30℃70％RH 1 week (168 hours)

Recommended reflow profile

This package should be assembled with IR reflow, full convection, or IR/convection. The allowable number of time with the reflow is max. 2 times. This must be done in the above-mentioned condition (after opening dry pack). Nitrogen reflow is recommended to inhibit the effects of oxidation and improve wettability. * Hand soldering using a soldering iron should be performed under the following

conditions: <Temperature: less than 350 °C, Time: less than 5 sec, Times: twice or less>

Pay sufficient attention not to let a soldering iron contact any parts other than leads.

Recommended bake conditions

When packages exceed the above-mentioned storage conditions after opening the dry pack, please bake them according to the following conditions:

Temperature Time Number of times

125±5℃ 20 - 36 hours Max. 2 times

Storage conditions from the baking to the reflow soldering are the same as the above-mentioned storage conditions.

*if products are shipped in tape & reel, please transfer them to heatproof trays before baking.

(Storage rank： MSL3)

Pre-heat

140 – 200℃

60 – 120sec

Time above 220℃:

Max. 60sec

Peak temp.： 260℃

Time above 255℃:

Max. 10sec

Time

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(Pa

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ag

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urf

ace)

7. Cleaning


（Rev.1.0）

7. Cleaning

7.1 Cleaning after BGA Soldering

Since BGA standoff *1) is very narrow after soldering, it is very difficult to remove the solder paste flux

residue between the BGA and the PCB. Solder paste that does not require cleaning after soldering is

recommended. Also, when selecting the solder paste that requires cleaning, cleaning condition need to be decided after detail

discussion with solder paste supplier. *1) Standoff: The distance between BGA mounted PCB surface and BGA package bottom surface.

7.2 General PCB Cleaning

7.2.1 PCB Cleaning

The flux residue after PCB production process may causes a leakage or migration between terminals. These

may affect the reliability. Cleaning is effective in removing flux sticking on the components and connection

terminals that require flux cleaning. Also, cleaning is effective in removing scattered solder balls that occurred

during reflow soldering. If “no-clean solder” is not used, it is still recommended to perform flux cleaning after

reflow soldering.

7.2.2 Cleaning Method

Standard cleaning methods for PCB include immersion cleaning, ultrasonic cleaning, spray cleaning, vapor

cleaning and so on. Hot water immersion ultrasonic cleaning is widely used. Regarding detail cleaning method,

please follow the recommendation from solder paste supplier and cleaning fluid supplier.

7.2.3 Water Cleaning

In case of using water soluble solder paste, in order to prevent moisture absorption, it is necessary to control

the staging time between solder paste printing and components mounting and reflow soldering. Regarding

operation time management, please follow the recommendation from solder paste supplier.

7.2.4 No Cleaning

For eliminating “Cleaning process” after reflow soldering, it is necessary to check the effect of halogen

content, especially chlorine content, in flux and to use solder paste with less flux residue. Before “no cleaning” is

implemented, please check that the solder is “no-clean solder” type and perform mounting evaluation and

reliability test by using actual PCB.

7.3 Others

(1) Cleaning time should be short, and cleaning temperature should be as low as possible. (2) Please be sure to check the quality (effect on the terminal) after cleaning. (3) If water adheres and remains on the BGA terminal after cleaning, there is a risk of causing troubles, so please

perform drying treatment thoroughly. (4) Please evaluate the influence by cleaning agent, diluent, water and pure water on the PCB and mounted

components thoroughly. Influence by acid, alkali, organic solvent and water should be considered as well.

8. Rework


（Rev.1.0）

8. Rework

Reuse of the BGA that is removed from the PCB after reflow soldering, will void the warranty. Please do not

reuse the removed BGA.

Also, in case of re-mounting new BGA on the PCB from which the BGA is removed, please perform soldering

of new BGA after cleaning the PCB surface and reapplying new solder paste.

The method of removing mounted BGA is as follows: Use a dedicated jig for removing the components, and

remove the BGA by melting solder connection while locally heating by high temperature air. Before heating the

BGA, preheat the BGA area and its surrounding. Preheating reduces high temperature heating time required for

removal, and minimizes the distortion and the deformation of the PCB.

Additionally, in case of PCB rework and reuse, please check the influence of damage, deformation,

mountability, reliability and so on of the PCB thoroughly by customer.

Fig 8.1 (Reference) Sketch of BGA Rework

(2) Heat by high temperature air

Operation flow (1) Preheat (Heat in advance) (2) Heat by high temperature air (In a short time) (3) Removal (Quickly)

PCB

Suction nozzle

(3) Removal

BGA

(1) Preheat

9．General Precautions for Use of Semiconductor Devices


（Rev.1.0）


Please follow the precautions of our semiconductor products mentioned below. For details on BGA, please also

check the notes mentioned in each chapter in this document.

9.1 Introduction

Epson’s semiconductor devices are designed and manufactured to assure trouble-free operation when used

under normal operating conditions. All products are subjected to stringent electrical and mechanical testing to

ensure reliability, but users are strongly recommended to observe the following precautions when designing

systems, handling or storing devices to minimize the chance of failure.

9.2 Storage

(1) Take care so that packages are not subjected to impact, vibration or water leakage.

(2) Do not store and use the product under the environment in which moisture condensation may be formed due

to rapid changes in temperature. Also, please do not apply load to the products during storage.

(3) When storing, avoid dusty locations or locations with corrosive gases.

(4) Before opening moisture-proof bag, please make sure that the moisture-proof bag is not broken or scratched.

Also check the silica gel in the bag has not absorbed moisture, after the bag is opened.

(5) When using after a long term of storage, use after confirming that terminal discoloration, solderability

deterioration and so on, does not occur.

9.3 Design and Handling

(1) Use ICs within the rated ranges of operating voltage, temperature, input/output voltage and current. Devices

may sometimes work properly for a short period of time even when used outside of rated ranges, but their

failure ratio may increase. Even within the rated conditions, failure ratio will change depending on the

operating temperature and voltage of embedded systems. This must be fully considered when designing

systems.

(2) When a noise such as spark and electrostatic is given from an input terminals, IC may malfunction. Pay

sufficient attention in product designing. Electromagnetic can cause ICs to operate erratically. Shield all

interference sources in equipment that uses ICs.

(3) Excessive electrical noise occurred to a power or input/output pin can cause ICs to latch up, resulting in device

malfunction or damage. If this occurs, turn off the power, solve the problem, then supply power again.

(4) Although all pins are equipped with an anti-electro static circuit, electro static beyond the capacity may lead

to breakage. Take appropriate countermeasures for ESD when handling ICs.

(5) Avoid using packing and transporting containers made of plastic, use electrically conductive containers. Also,

special care must be taken when handling ICs, by wearing an antistatic wrist strap or taking other possible

measures.

(6) Use a soldering iron and test circuits without high voltage leakage and use those with grounding.

(7) Storage conditions after opening a moisture proof-bag, soldering method and soldering temperature must meet

the requirements specified by Epson for respective products.

(8) Minimize mechanical stress to a printed circuit board during or after soldering.



（Rev.1.0）

(9) As for a surface mount device, the land of a PCB and the lead of a package will be soldered with those both

surfaces in contact. Although Epson is shipping products securing sufficient lead flatness for soldering, when

handling, take care not to apply force which leads to deformation of the lead.

(10) Use the IC under the proper temperature and humidity. The humidity must not be more than 85% (no dew

condensation). In the environment where the IC is directly exposed to acid gas such as SO2, or exposed to

dust or salt, it may cause electrical leakage between leads or corrosion. In order to prevent such problems, in

above environment, apply corrosion-proof coatings to PCB and ICs.

(11) Avoid the following as much as possible, since mechanical vibration, shock, continuous stress, sudden

temperature change and so on, may cause package cracks and/or wire breakage.

(12) In some packages, a part of the signal line is exposed on the surface of the package. Pay attention to

contamination of the package when using these products. Also avoid handling products with bare hands.

(13) Light irradiation to ICs may cause the characteristics change of IC. To prevent IC from malfunction, consider

following points for IC mounted PCB and IC used products.

> In product design and assembly, consider the product structure so that IC (especially IC chip) is shielded

from light in actual use.

> In testing process, provide light-shielded environment for the semiconductor device under test.

> Regarding light shielding of IC, consider the light shielding for the surface, back, and side of IC chip.

Revision History


（Rev.1.0）

Revision History

Attachment-1

Rev. No. Date Page Category Contents

Rev 1.0 2018/07/02 All New New release

International Sales Operations

America Epson America, Inc.

Headquarter:

3840 Kilroy Airport Way

Long Beach, California 90806-2452 USA

Phone: +1-562-290-4677

San Jose Office:

214 Devcon Drive

San Jose, CA 95112 USA

Phone: +1-800-228-3964 or +1-408-922-0200

Europe Epson Europe Electronics GmbH Riesstrasse 15, 80992 Munich,

Germany

Phone: +49-89-14005-0 FAX: +49-89-14005-110

Asia Epson (China) Co., Ltd. 4th Floor, Tower 1 of China Central Place, 81 Jianguo Road, Chaoyang

District, Beijing 100025 China

Phone: +86-10-8522-1199 FAX: +86-10-8522-1120

Shanghai Branch Room 1701 & 1704, 17 Floor, Greenland Center II,

562 Dong An Road, Xu Hui District, Shanghai, China

Phone: +86-21-5330-4888 FAX: +86-21-5423-4677

Shenzhen Branch Room 804-805, 8 Floor, Tower 2, Ali Center,No.3331

Keyuan South RD(Shenzhen bay), Nanshan District, Shenzhen

518054, China

Phone: +86-10-3299-0588 FAX: +86-10-3299-0560

Epson Taiwan Technology & Trading Ltd. 15F, No.100, Songren Rd, Sinyi Dist, Taipei City 110. Taiwan

Phone: +886-2-8786-6688

Epson Singapore Pte., Ltd.

1 HarbourFront Place,

#03-02 HarbourFront Tower One, Singapore 098633

Phone: +65-6586-5500 FAX: +65-6271-3182

Seiko Epson Corp.

Korea Office 19F, KLI 63 Bldg, 60 Yoido-dong,

Youngdeungpo-Ku, Seoul 150-763, Korea

Phone: +82-2-784-6027 FAX: +82-2-767-3677

Seiko Epson Corp.

Sales & Marketing Division

Device Sales & Marketing Department

421-8, Hino, Hino-shi, Tokyo 191-8501, Japan

Phone: +81-42-587-5816 FAX: +81-42-587-5116

Document Code: 3990-0002

First Issue July 2018 in JAPAN

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